Attendee Interaction

[Ianim8]

Good afternoon folks,

Is there anything in the way of a handheld device that allows
attendees to participate during a presentation? Perhaps an app that
would run on a Blackberry? I am looking for something that would allow
the attendees to answer questions, provide feedback, ask questions,
and even connect with other attendees. On top of that, I need to be
able to track the usage of the software/hardware.

I am open to solutions that work with Keynote, Powerpoint, or other
applications.

Anybody know of any good Powerpoint mailing lists?

Thanks, any suggestions would be greatly appreciated.

Glen